Rheem ECO POU 3.5
0.95 UEF DOE CCD · 2026-09-19Grade F: where this UEF sits among the 271 models in its class, lowest (G) to highest (A). A position, not an official label. How the grade is set
An electric tankless unit, very small draw pattern (small units - a single bathroom, or a point-of-use heater under a sink).
For a check on the Rheem ECO POU 3.5: it uses 622 kWh of electricity a year at the very small draw pattern, the standard daily hot-water usage DOE tests against. That is 7 kWh above the class median of 615 kWh, and it ranks 152nd lowest in energy use among 271 models.
Energy use per year
622 kWh a year
Computed by this site from the registry's UEF and the federal test's daily hot-water draw for this draw pattern. What it costs depends on the electricity rate where you live.
That is above the median of 615 kWh for the 271 models registered in the same heater type and draw pattern; it ranks 152 of 271, lowest energy first.
Solid line: this model (622 kWh). Dashed line: the class median.
Min 562 kWh Median 615 kWh Max 649 kWh
What it costs to run where you live
What the registry files
- UEF (Uniform Energy Factor) how much hot water you get for each unit of energy the heater uses
- 0.95 DOE CCD · 2026-09-19 Compared only with other models registered as an electric tankless unit at the very small draw pattern.
- Draw Pattern the standard daily usage profile DOE tests the unit against
- Very small DOE CCD · 2026-09-19
- Maximum Gallons Per Minute how many gallons a minute it can heat while running continuously
- 0.3 gal/min DOE CCD · 2026-09-19
What it costs to install
$1,303–$1,814 installed
Not a quote — a modeled range of what installers have charged for this class of unit; your price will vary with labor rates, access, and local code requirements.
Escalation indexes: equipment (BLS PPI) latest available: August 2026; labor (BLS ECI) latest available: April 2026 to June 2026.
NLR REMDB (BLS PPI/ECI escalated) · 2026-04-01Safety record
No CPSC recall names this model.
Checked against the CPSC recall database. CPSC does not publish a model-level match for this product category, so this list is curated by hand from the manufacturer's recall filings.
CPSC · 2026-09-24What these figures mean
How this compares
The closest models in the same class — same fuel, type and draw pattern.
Keep going
How every figure on this page is calculated
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Find what replaces your water heater
Enter the model number off your old unit and see what is on file today, with the yearly cost difference.
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Find a water heater that fits
Three questions — fuel, hot water need, install space — narrow every model on file to the ones that fit.
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What a water heater costs to run
Prices a unit's efficiency against your own utility's filed tariff for your ZIP code.
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How to size a tankless water heater by GPM
Answered from what models in this size actually file.
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Water heaters
Every model on file with the Department of Energy, by heater type.
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All electric tankless water heaters
Electric instantaneous units, sized by flow rate rather than tank gallons.
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Every Rheem model on file
What this brand files, by heater type.
UEF 0.95 · Grade F Price it on your ZIP
The figure of 622 kWh is computed by this site, not the registry. It combines the registry's UEF, the ratio of hot water delivered to energy used, of 0.95 with the DOE test's daily hot-water draw for the very small draw pattern. The fuel is electricity, and the source is DOE CCD, retrieved 2026-09-19. The figure holds only at that test draw; energy use at any other draw is not available here. The registry also lists a maximum flow rate in gallons per minute of 0.3. The steps of the calculation are set out in the methodology for the annual figure.
Against the 271 models registered as an electric tankless unit at the very small draw pattern, the ECO POU 3.5 sits 7 kWh above the class median of 615 kWh. Its rank is 152nd lowest energy use of 271, which places it in the second-highest quarter of its class for energy use. The registry data used here gives the median and the rank only; it does not show how widely the class is spread. The very small draw pattern covers small units, such as a bathroom or a point-of-use heater under a sink. The figure is relevant to a reader verifying a unit for that use. It does not describe a unit serving a larger household, where the test draw is different.
The running cost is not written in this text because it depends on your own utility electricity tariff. Multiply 622 kWh by your rate per kilowatt-hour, or use the cost calculator on your own ZIP. At the class median of 615 kWh, the gap of 7 kWh a year would be priced at that same rate. The installed price range appears in its own block on this page, with its source and date, as a modeled range and not a quote. If the unit must serve a larger draw than the very small pattern, the 622 kWh figure does not carry over, and the selector by fuel, space and size is the place to compare. To stay within this class, find a same-class replacement by model number.
DOE CCD · 2026-09-19